Re: why is anybody surprised?
I'd take a hydrogen fire any day of the week. Heck, a hydrogen fire may be darn near invisible, it may burn at an insanely hot temperature, and it may gnaw its way through darn near any material.
But cut off its oxygen, and it dies. Cut off the fuel, and it dies.
A florine fire is a special beast. It reacts with nearly anything to release oxygen. Its reactions are insanely exothermic. And it reacts with nearly anything. That means it brings its own oxygen, heat, and fuel to the area it resides in. It's basically the devil's diarrhea, turning anything it touches into its own special little version of Hell.
I don't honestly know of anything that would extinguish a florine fire. Chilled nitrogen may snuff it out, but as soon as the nitrogen is displaced it would start right back up. It seems to be one of those 'sit back and wait for it to burn itself out' deals. Not to mention the devil's fart of insanely dangerous by-products a florine fire produces.
There's just some chemicals you just 'nope' right on past and start walking faster.